Detonative cleaning apparatus mounting system

ABSTRACT

An apparatus for cleaning a surface within a vessel has an elongate combustion conduit extending from an upstream end to a downstream end. The downstream end is associated with an aperture in the wall of the vessel and is positioned to direct a shockwave toward the surface. At least one hanger supports the combustion conduit at least one location along a length of the combustion conduit. A penetration conduit is positioned between the wall aperture and an associated portion of the combustion conduit. Means couple the combustion conduit to the penetration conduit so as to accommodate relative longitudinal movement and/or relative angular movement.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and incorporates in its entiretyby reference U.S. Provisional Patent Application Ser. No. 61/028,491,filed Feb. 13, 2008, entitled “Detonative Cleaning Apparatus Mounting.”

TECHNICAL FIELD OF THE INVENTION

The disclosure relates to industrial equipment. More particularly, thedisclosure relates to the detonative cleaning of industrial equipment.

BACKGROUND OF THE INVENTION

Surface fouling is a major problem in industrial equipment. Suchequipment includes furnaces (coal, oil, waste, etc.), boilers,gasifiers, reactors, heat exchangers, and the like. Typically, theequipment involves a vessel containing internal heat transfer surfacesthat are subjected to fouling by accumulating particulate such as soot,ash, minerals and other products and byproducts of combustion, moreintegrated buildup such as slag and/or fouling, and the like. Suchparticulate build-up may progressively interfere with plant operation,reducing efficiency and throughput and potentially causing damage.Cleaning of the equipment is therefore highly desirable and is attendedby a number of relevant considerations. Often direct access to thefouled surfaces is difficult. Additionally, to maintain revenue, it isdesirable to minimize industrial equipment downtime and related costsassociated with cleaning. A variety of technologies have been proposed.Such systems are often identified as “soot blowers” after an exemplaryapplication for the technology.

Basic soot blower configuration is the scheme lance soot blower.Additionally, combustion soot blower technologies have been proposed.Recent examples include those of U.S. Pat. Nos. 7,011,047 and 7,442,034and US Patent Publication Nos. 20050126594 and 20050130084, both nowabandoned, the disclosures of which are incorporated by reference intheir entireties herein as if set forth at length.

SUMMARY OF THE INVENTION

Accordingly, one aspect of the disclosure involves an apparatus forcleaning a surface within a vessel. An elongate combustion conduitextends from an upstream end to a downstream end associated with anaperture in the wall of the vessel and positioned to direct a shockwavetoward the surface. One or more hangers support the combustion conduitat one or more locations along a length of the combustion conduit. Apenetration conduit is positioned between the wall aperture and anassociated portion of the combustion conduit. Means couple thecombustion conduit to the penetration conduit so as to accommodate oneor both of relative longitudinal movement and relative angular movement.

In various implementations, the means for coupling may accommodate therelative longitudinal movement via a slip fit and the relative angularmovement via flexing. The slip fit may be of an apertured plate held bya bellows or expansion joint. The flexing may be of the bellows orexpansion joint.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic side view of a soot blower associatedwith an industrial furnace.

FIG. 2 is a top view of the soot blower of FIG. 1.

FIG. 3 is an enlarged side view of a discharge/outlet end of the sootblower of FIG. 1.

FIG. 4 is a transverse sectional view of the soot blower of FIG. 3.

FIG. 5 is a partial vertical longitudinal sectional view of the sootblower end portion.

FIG. 6 is a view of a damper of the soot blower of FIG. 1.

FIG. 7 is a sectional view of the damper of FIG. 6.

FIG. 8 is a side view of an alternate soot blower.

FIG. 9 is a top view of the soot blower of FIG. 8.

FIG. 10 is a view of a first pair of thrust reaction plates secured to aflange joint.

FIG. 11 is an end view of the plates and joint of FIG. 10.

FIG. 12 is an X-ray view of one of the plates of FIG. 10.

FIG. 13 is a view of the plate of FIG. 12.

FIG. 14 is an end view of the plates and joints carrying devises.

FIG. 15 is an end view of plates and joints carrying first alternativelyoriented devises.

FIG. 16 is an end view of plates and joints carrying secondalternatively oriented devises.

FIG. 17 is a view of alternate thrust reaction plates secured to ajoint.

FIG. 18 is an end view of the plates and joint of FIG. 17.

FIG. 19 is a view of a single thrust reaction plate secured betweenflanges of a joint.

FIG. 20 is an end view of the plate and joint of FIG. 19.

FIG. 21 is a top view of an alternate embodiment of the sootblower ofFIG. 1.

FIG. 22 is a side view of the sootblower of FIG. 21.

FIG. 23 is an end view of the thrust reaction plates and joint of FIG.22.

FIG. 24 is a perspective view of a thrust reaction plate of FIG. 23.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

FIG. 1 shows a vessel (e.g., a boiler) 20 in a building 21. One or moresoot blower apparatus (soot blowers) 22 are positioned to clean surfaceswithin the vessel interior 78. The exemplary vessel comprises a wall 24.The exemplary wall 24 may include a structural and/or insulative outerlayer 26 and an inner layer 28. In high temperature locations along thewall 24, the inner layer 28 may be a heat transfer layer formed of fluid(e.g., water)-carrying tubes. Exemplary tubes are welded together toform a membrane wall. In lower temperature locations, the inner layer 28may be a steel plate. For further structural reinforcement againstinternal or external pressure loads, the wall 24 may includereinforcements commonly known as buckstays 30. Exemplary buckstays 30are steel I-beams secured to each other and to the remaining wallstructure to form a rigid enclosure. The wall 24 is subject to thermalgrowth as the vessel temperature increases. The growth may beaccommodated by suspending the vessel via the buckstays 30 from arelatively fixed building structure such as a ceiling 32. As the vesselheats, the wall 24 grows vertically downward.

Each soot blower 22 includes an elongate combustion conduit 36 extendingfrom a first (e.g., an upstream/distal/inlet end) 38 away from thevessel wall 24 to a second (e.g., downstream/proximal/outlet) end 40closely associated with the wall 24. Optionally, however, the end 40 maybe well within the vessel interior 78. In operation of each soot blower22, combustion of a fuel/oxidizer mixture within the conduit 36 isinitiated proximate the upstream end 38 (e.g., within an upstreammost10% of a conduit length) to produce a detonation wave which is expelledfrom the downstream end 40 as a shock wave along with associatedcombustion gases for cleaning surfaces within the interior volume of thefurnace. Each soot blower 22 may be associated with a fuel/oxidizersource 42. Such source or one or more components thereof may be sharedamongst the various soot blowers. An exemplary source includes aliquified or compressed gaseous fuel cylinder 44 and an oxygen cylinder46 in respective containment structures 48 and 50.

In one example, there is a single fuel (e.g., propane) and a singleoxidizer (e.g., the pure oxygen). In second example, the oxidizer is afirst oxidizer such as essentially pure oxygen. A second oxidizer may bein the form of shop air delivered from a central air source 52. In thesecond example, air may be stored in an air accumulator 54. Fuel,expanded from that in the cylinder 46 may be stored in a fuelaccumulator 56. Each exemplary source 42 is coupled to the associatedconduit 36 by appropriate plumbing. Similarly, each soot blower 22includes a spark box 60 coupled to an igniter 61 for initiatingcombustion of the fuel oxidizer 4 mixture and which, along with thesource 42, is controlled by a control and monitoring system 62.

In exemplary embodiments of the second example, the fuels arehydrocarbons. In particular exemplary embodiments, both fuels are thesame, drawn from a single fuel source but mixed with distinct oxidizers:essentially pure oxygen for the predetonator mixture; and air for themain mixture. Exemplary fuels useful in such a situation are propane,MAPP gas, or mixtures thereof. Other fuels are possible, includingethylene and liquid fuels (e.g., diesel, kerosene, and jet aviationfuels). The oxidizers can include mixtures such as airloxygen mixturesof appropriate ratios to achieve desired main and/or predetonator chargechemistries. Further, monopropellant fuels having molecularly combinedfuel and oxidizer components may be options.

FIG. 1 shows further details of an exemplary soot blower 22. Theexemplary conduit 36 may be formed by a series of doubly flanged conduitsections or segments arrayed from upstream to downstream and adownstream nozzle conduit section or segment 72 having a downstreamportion 74 extending through an aperture 76 in the wall and ending inthe downstream end or outlet 40 exposed to the vessel interior 78. Theterm nozzle is used broadly and does not require the presence of anyaerodynamic contraction, expansion, or combination thereof. Exemplaryconduit segment material is metallic (e.g., stainless steel). The outlet40 may be located further within the vessel if appropriate support andcooling are provided. Within the vessel interior 78 are furnace interiortube bundles 80, the exterior surfaces of which are subject to foulingand which are to be cleaned by the soot blower 22.

A fuel/oxidizer charge may be introduced to the conduit interior in avariety of ways. As noted above, there may be one or more distinctfuel/oxidizer mixtures. Such mixture(s) may be premixed external to thedetonation conduit, or may be mixed at or subsequent to introduction tothe conduit. For example, there may be distinct introduction of twodistinct fuel/oxidizer combinations: a predetonator combination; and amain combination. There may also be a purge gas conduit connected to apurge gas port. An end plate may be bolted to the upstream flange of theupstream segment to seal the upstream end of the combustion conduit andpass through the igniter/initiator 61 (e.g., a spark plug) having anoperative end in the conduit interior.

In operation, at the beginning of a use cycle, the combustion conduit isinitially empty except for the presence of air (or other purge gas orflue gas). The fuel(s) and oxidizer(s) are introduced.

With the charge(s) introduced, the spark box is triggered to provide aspark discharge of the initiator igniting charge (or the predetonatorcharge in a multi-charge example). The predetonator charge (or singlecharge) may be selected for very fast combustion chemistry, the initialdeflagration quickly transitioning to a detonation producing adetonation wave. Once such a detonation wave occurs, it is effective topass through the rest of the charge (or the main charge which might,otherwise, have sufficiently slow chemistry to not detonate within theconduit of its own accord). The wave passes longitudinally downstreamand emerges from the downstream end 40 as a shock wave within thefurnace interior, impinging upon the surfaces to be cleaned andthermally and mechanically shocking to typically at least loosen thecontamination. The wave will be followed by the expulsion of pressurizedcombustion products from the detonation conduit, the expelled productsemerging as a jet from the downstream end 40 and further completing thecleaning process (e.g., removing the loosened material). After oroverlapping such venting of combustion products, a purge gas (e.g., airfrom the same source providing the main oxidizer and/or nitrogen) isintroduced through the purge port to drive the final combustion productsout and leave the detonation conduit filled with purge gas ready torepeat the cycle (either immediately or at a subsequent regular intervalor at a subsequent irregular interval (which may be manually orautomatically determined by the control and monitoring system).Optionally, a baseline flow of the purge gas may be maintained betweencharge/discharge cycles so as to prevent gas and particulate from thefurnace interior from infiltrating upstream and to assist in cooling ofthe detonation conduit.

In various implementations, internal surface enhancements maysubstantially increase internal surface area beyond that provided by thenominally cylindrical and frustoconical segment interior surfaces. Theenhancement may be effective to assist in the deflagration-to-detonationtransition or in the maintenance of the detonation wave.

The apparatus may be used in a wide variety of applications. By way ofexample, just within a typical coal-fired furnace, the apparatus may beapplied to: the pendants or secondary superheaters, the convective pass(primary superheaters and the economizer bundles); air preheaters;selective catalyst removers (SCR) scrubbers; the baghouse orelectrostatic precipitator; economizer hoppers; ash or otherheat/accumulations whether on heat transfer surfaces or elsewhere, andthe like. Similar possibilities exist within other applicationsincluding oil-fired furnaces, black liquor recovery boilers, biomassboilers, waste reclamation burners (trash burners), and the like.

To support the conduit 36, the exemplary soot blower 22 includes one ormore hangers 100 and 102. The exemplary hanger 100 is positionedrelatively upstream and the exemplary hanger 102 relatively downstream.The exemplary hanger 100 couples the conduit 36 to relatively fixedbuilding structure, bypassing the vessel 20. Exemplary relatively fixedbuilding structure is as a transverse horizontal I-beam 104 or theceiling 32. The exemplary hanger 100 connects to a support point 106along the conduit 36 such as a hanger eyelet and to another eyelet 108along the I-beam 104. The exemplary hanger 100 is a spring hanger, moreparticularly constant load spring hanger. Exemplary spring hangers areavailable from LISEGA, Inc., Newport, Tenn.

The exemplary hanger 102 couples the conduit 36 to the vessel 20. In theexemplary embodiment, the hanger 102 is coupled to an eyelet 110 securedto one of the buckstays 30 above the conduit 36. The exemplary hanger102 connects to a collar 112 encircling the conduit in a slip fit(discussed further below). The exemplary hanger 102 is a spring hanger(e.g., a simple spring hanger, not a constant load spring hanger).

The soot blower 22 includes means for resisting recoil of the conduit.The exemplary means for resisting recoil may couple the conduit torelatively fixed building structure to transfer recoil forces to thebuilding structure (and not the wall 24). FIGS. 1 and 2 show means asincluding a pair of struts 120 (e.g., respectively to the left and rightof the conduit 36) coupling the conduit to vertical posts 122. Theexemplary struts 120 include an elongate shaft 124 having upstream anddownstream ends. At the respective upstream and downstream ends, joints126 and 128 are provided respectively engaging mating coupling elements130 and 132 on the conduit 36 and posts, respectively. The exemplaryjoints 126 and 128 are rods each having a threaded first end mated toend caps of the shaft and having an eyelet second end carrying anapertured ball. The exemplary couplings 130 and 132 are mating devisescarrying pins extending through the associated balls. As is discussedfurther below, the exemplary upstream couplings 130 are mounted to oneor more plates 140, 142. Exemplary plates 140 and 142 are respectivelymounted to the right and left sides of the conduit 36. Exemplary plates140 and 142 are mounted to a downstream face of an upstream flange ofone of the sections of the conduit 36. The coupling elements 130 are, inturn, mounted to the downstream faces of the plates 140 and 142.

Upon firing of the conduit, recoil forces tend to drive the conduit awayfrom the vessel 20. Slip fit between the collar 112 and the conduit mayallow a certain amount of movement. However, the movement is resisted bytensile force transmitted through the struts 120. As is discussedfurther below, the struts may include resilient dampers to smoothlyabsorb the recoil forces and limit peak force loads transferred to thebuilding. An exemplary recoil is limited/constrained to a value of lessthan about 10 cm (e.g. a value in the range of 1-6 cm, more narrowly2.5-5 cm).

The thermally-induced vertical movement of the vessel 20 may tend tocause associated local vertical movement of the conduit. Even if thiscan be partially matched by compliance in the hanger 100, it may beimpractical to entirely so address. The result is that the conduit willtend to rotate to a slightly outlet-down orientation. A rigid mountingof the conduit to the vessel would potentially interfere with properconduit operation across the anticipated range of vessel verticaldisplacement. Also, there may be relative horizontal displacement.Accordingly, referring to FIG. 3, the exemplary apparatus includes meansfor coupling the conduit to the vessel so as to accommodate relativelongitudinal movement (e.g., the recoil) and relative angular movement(e.g., associated with vertical thermal expansion of the vessel or othervertical or horizontal relative movements). The exemplary means includesa penetration conduit 150 which may be rigidly mounted to the wall 24.For example, the penetration conduit 150 may be in a friction fit or aninterference fit with the outer layer 26 or may be secured thereto viabrackets or other mounting elements. The exemplary penetration conduit150 includes an upstream mounting flange 152 outside the vessel. Atubular portion 154 extends from the mounting flange 152 through thewall 24 to an exemplary downstream/outlet end 156 (e.g., a rim). Adownstream end portion 155 of the nozzle at the outlet 40 may protrudebeyond the rim 156.

Referring to FIG. 5, an annular space 160 between the interior surface162 of the tubular portion 154 and the exterior surface 164 of theconduit downstream portion 74 may have sufficient radial span DR toaccommodate relative angular movement of the combustion conduit 36relative to the penetration conduit 150 and wall 24. The relativeangular movement may include movement characterized by rotation about ahorizontal transverse axis (e.g., associated with a pure verticalmovement of the vessel relative to one or more upstream supportlocations of the conduit). The relative angular movement may includemovement characterized by rotation about a vertical transverse axis(e.g., associated with a pure horizontal movement of the vessel relativeto one or more upstream support locations of the conduit). In additionto these respective pitch and yaw movements, there, potentially may be aroll movement about a longitudinal axis. The span DR may also beeffective to accommodate transverse translation movements of up to DR.An exemplary range of angular movement is up to 5° in any direction (fora total range of 10°) from a neutral coaxial condition (e.g., to 0.5-5°in any direction or, more narrowly, 1-4°).

The space 160 may be sufficiently sealed to limit exfiltration (outwardflow of gases from the vessel interior if a positive pressure system)and/or infiltration (inward flow of air in the case of a negativepressure system). To do this, a closure plate 170 is positioned outsidethe vessel to provide a higher degree of relative sealing between thepenetration conduit and combustion conduit than would be associated withthe radial gap of span DR. Referring to FIGS. 4 and 5, in the exemplaryimplementation, the plate 170 has a central aperture 172 which closelyaccommodates the exterior surface 174 of the conduit downstream portion74. An exemplary accommodation is a close radial sliding fit (muchcloser than DR). However, for a positive pressure system, in particular,the gap may be closed (e.g., by a sealing/structural weld). Theexemplary plate 170 is formed in two 180° segments permitting easyassembly over the combustion conduit. The close accommodation of theplate 170 to the combustion conduit requires that relative angularmovement between the plate 170 and the flange 152 be accommodated. Asseen in FIG. 5, this relative movement may be accommodated by a flexiblemember 180. An exemplary flexible member 180 is formed as an expansionjoint.

An exemplary expansion joint is a single or multiple arch elastomericexpansion joint. The illustrated expansion joint is a single arch,doubly flanged expansion joint such as is available from The MercerRubber Company of Hauppauge, N.Y., US. The exemplary expansion joint 180has a flexible arch 182 between a first flange 184 and a second flange186. The first flange 184 is bolted to the plate 170. The second flange186 is bolted to the flange 152. The arch may flex to accommodate therelative angular movement. In implementations including those with afixed non-sliding fit between the plate 170 and the combustion conduit36, the arch 182 may also accommodate relative longitudinaldisplacement. Metallic expansion joints may, however, be used (e.g.,where advantageous due to high temperature exposure).

For insulation and further sealing, insulation material 190 ispositioned within the annular space 160. Exemplary insulation materialcomprises fibrous material such as a batt or mat of mineral wool and/orglass fiber which also provides a degree of thermal insulation. Thematerial may be longitudinally captured between the plate 170 and anannular clamp 192 (e.g., a stainless steel band clamp clamping an endportion of the insulation batt/mat to the conduit downstream portion74). With sliding fit between the plate 170 and the conduit 36, relativelongitudinal recoil movement of the combustion conduit 36 relative tothe wall will be associated with telescoping movement of the downstreamportion 74 relative to the penetration conduit 150. The initial recoilmay longitudinally compress the insulation 190. A return may re-expandthe insulation.

For damping recoil and providing a return force, FIGS. 6 and 7 showdamper units 200 which may serve as the joints 126 and/or 128. Eachdamper unit has a threaded first end portion 202 and a ball-carryingsecond end portion 204 (i.e., for forming a ball joint). In theexemplary damper unit 200 one of the end portions forms a piston whereasthe other forms a cylinder. The exemplary first end portion 202 isformed on a first shaft having an opposite end secured (e.g., threaded)into a piston head 206. The exemplary second end portion 204 is along asecond shaft whose opposite end is secured to a cylinder 210. Within thecylinder 210, at opposite ends of the head 206 are resilient (e.g.,rubber or elastomer) disks 212 and 214. In the exemplary configuration,extension of the damper resiliently compresses the disk 212 whereascompression resiliently compresses the disk 214. The disks 212 and 214may be preloaded (i.e., both are under compression when there is no netcompressive or tensile force across the damper unit 200). With theexemplary damper unit 200, recoil of the conduit further compresses thedisk 214, absorbing the recoil energy and, then, at least partiallyrelaxing to return the combustion conduit to its initial position.

Alternative dampers may be hydraulic snubbers as are available fromPiping Technology&Products, Inc. of Houston, Tex. Other devices areavailable from Taylor Devices Inc. of North Tonawanda, N.Y. as are usedin aircraft landing gear shock absorbers. These may be particularlyrelevant in systems absorbing recoil via compression rather thantension.

Referring back to FIGS. 1 and 2, the struts 120 have sufficient lengthto accommodate vertical movement by pivoting at axes of the couplingelements 132 while not substantially affecting the longitudinal positionof the conduit 36 relative to the wall 24. FIGS. 8 and 9, however, showan alternative configuration wherein a sliding thrust joint 250 isprovided. The joint 250 can vertically slide along fixed buildingstructures such as a vertical I-beams (posts) 252 and 254 to accommodatevertical movement. Recoil thrust loads are transferred through the joint250 to the structure 252 and 254.

FIG. 9 shows respective posts 252 and 254 on opposite sides of theconduit 36. The exemplary joint 250 includes pieces of low frictionmaterial 256 and 258 respectively sliding along the downstream faces ofthe downstream flanges of the posts 252 and 254. Exemplary low frictionmaterial is polytetrafluoroethylene (PTFE) or an ultra high molecularweight (UHMW) plastic material. The low friction material is sandwichedbetween the associated post flange and an associated robust thrust plate260 and 262. Exemplary thrust plates may be similarly formed to theplates 140 and 142 of the first embodiment. Exemplary thrust plates areintegrated with a flanged pipe joint 266 between two segments of theconduit 36. Retainer brackets 270 and 272 may capture outboard edges ofthe respective post flanges to help guide vertical movement.

FIGS. 10 and 11 have separate plates 260 and 262 attached to the backface of the downstream flange 280 of one of the conduit segments (matedto the upstream flange 282 of the next segment). FIGS. 12 and 13 show anindividual one of the plates 260, 262 as including two through-holes 283for bolting with the flanges along the bolt circle of the flanges andtwo additional holes 284 for mounting the coupling elements 130 or thelow friction material 256, 258 (not shown). FIGS. 14-16 show alternatemounting configurations for the coupling elements 130 or the lowfriction material 256, 258.

FIGS. 17 and 18 show an alternate plate configuration wherein plates 300and 302 replace plates 260 and 262. The plates 300 and 302 are welded tothe OD of the flange 280.

FIGS. 19 and 20 show a single plate 310 having lateral portions 312 and314 which respectively replace the plates 260 and 262. The plate 310 isshown sandwiched between the flanges 280 and 282, having a centralaperture 316 and a bolt hole circle 320 corresponding to those of theflanges 280 and 282 and receiving the bolts securing the flanges 280 and282. Each of the three exemplary configurations may have differentadvantages. The welded construction of FIGS. 17 and 18 allows easyretrofitting without need to remove any bolts from the flanges 280 and282. However, the welds are directly loaded by the recoil force. Also,the loadpath of the recoil force is spaced outboard of the flange outerdiameter (OD). This relatively large radial spacing may causeundesirably high bending loading on the flange 280. The FIGS. 10 and 11plates may require only partial unbolting and without need to separatethe flanges 280 and 282. The force path is brought radially inward andmay act more directly against the faces of the flanges, therebydecreasing chance of damage to the flanges. The FIGS. 19 and 20embodiment may have a radially outboard force transmission but moreevenly circumferentially distributes this force to the associatedmoments. However, in a retrofit application, it requires full jointdisassembly. It may also require use of an additional gasket andreplacement of relatively short bolts with relatively longer bolts.

Referring to FIGS. 21 and 22, an alternative embodiment of the dampingunit 400 is shown. The unit 400 comprises a plurality of cylindricalelastomer bumpers 491, such as model number TCB-2 supplied by EFDYN. Asseen in FIGS. 21 and 22, four bumpers 491 are arranged along a rod 493which is threaded into a standard load strut 420. Referring to FIGS. 23and 24, the thrust plates 460 and 462 attach to the rear flange 480 ofthe combustor conduit 436. The thrust plates 460 and 462 are similar tothe thrust plate discussed in connection with the previous embodimentswith an aperture 497 provided for the rod 493 instead of connectingelements 130 or low friction material 256, 258. Referring back to FIGS.21 and 22, each thrust plate 460 and 462 is clamped between two of theelastomer bumpers 491. A small preload is applied to the bumpers 491 bynut and washer assemblies 494 on each side. Each nut and washer assembly494 includes two nuts 495 having a split ring style lock washer 496between them. Tightening the two nuts 495 together locks them in placeon the threaded rod 493.

The elastomer bumpers 491 arranged in this fashion act as aspring/damper system in both recoil (from the initial detonation thrustload) and in rebound as the kinetic energy absorbed by the bumpers 491is released and pushes the combustor conduit 436 back toward the vesselwall 424.

The elastomer bumpers 491 having a wide range of load ratings may beselected for different combustor conduit diameters and thrust loads.Accordingly, this damping unit is easily scalable up and down forvarious combustor diameters and thrust loads.

The damping unit 400 has been demonstrated in the field and is capableof installation as a retrofit to an existing sootblower or as part of anew installation. Testing in the field for a twelve inch (12″) diametercombustor conduit showed about a half inch (0.5″) total recoil from theinitial blast, with a sinusoidal decaying motion of the combustor thatwas completely damped to rest in four to five cycles of motion. Thefield testing showed nearly a reduction factor of four (4) in loadtransmitted through the struts to the vessel building structure when theelastomer bumpers 491 were utilized. This reduction is very significantas it greatly reduces the amount of local reinforcement customers mustadd to their vessel building structure for mounting of combustors.

One or more embodiments of the present invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, the invention may be adapted for use with a variety ofindustrial equipment and with variety of soot blower technologies.Aspects of the existing equipment and technologies may influence aspectsof any particular implementation. Accordingly, other embodiments arewithin the scope of the following claims.

1. An apparatus for cleaning a surface within a vessel, the apparatus comprising: an elongate combustion conduit extending from an upstream end to a downstream end associated with an aperture in a wall of the vessel and positioned to direct a shock wave toward said surface; means for movably supporting the combustion conduit at one or more locations along a length of the combustion conduit; a penetration conduit between the wall aperture and an associated portion of the combustion conduit; and means for coupling the combustion conduit to the penetration conduit so as to accommodate at least one of relative longitudinal movement and relative angular movement.
 2. The apparatus of claim 1 wherein: the means for coupling accommodates both said relative longitudinal movement and said relative angular movement.
 3. The apparatus of claim 1 wherein: the means for coupling accommodates said relative longitudinal movement via a slip fit; and the means for coupling accommodates the relative angular movement via flexing.
 4. The apparatus of claim 1 wherein: the means for coupling permits at least 0.1 m of said relative longitudinal movement and at least 1° of said relative angular movement, said relative angular movement being about a transverse horizontal axis.
 5. The apparatus of claim 4 wherein: the means for coupling provides no more than 1.0 m of said relative longitudinal movement and no more than 5° of said relative angular movement.
 6. The apparatus of claim 1 wherein the means for coupling comprises: a bellows having an upstream end and a downstream end; a plate secured to the bellows upstream end and having an aperture accommodating the combustion conduit in a slip fit; and an upstream end flange of said penetration conduit secured to the bellows downstream end.
 7. The apparatus of claim 6 wherein: the plate is formed in exactly two segments.
 8. The apparatus of claim 6 wherein: the means for coupling further comprises a fibrous layer surrounding the combustion conduit within the bellows and the penetration conduit.
 9. The apparatus of claim 1 further comprising: means for restraining the combustion conduit against thrust movement.
 10. The apparatus of claim 9 wherein the means for restraining comprises: at least two struts coupling the combustion conduit to a fixed building structure.
 11. The apparatus of claim 10 wherein: each of the struts comprises a damper.
 12. The apparatus of claim 11 wherein: the dampers are hydraulic dampers.
 13. The apparatus of claim 11 wherein: the dampers are resilient non-hydraulic dampers.
 14. The apparatus of claim 1 wherein: the means for movably supporting comprises one or more spring hangers.
 15. The apparatus of claim 1 wherein: the combustion conduit comprises a plurality of segments assembled end-to-end.
 16. An apparatus for cleaning a surface within a vessel, the apparatus comprising: an elongate combustion conduit extending from an upstream end to a downstream end associated with an aperture in a wall of the vessel and positioned to direct a shock wave toward said surface; one or more hangers supporting the combustion conduit at one or more locations along a length of the combustion conduit; a penetration conduit between the wall aperture and an adjacent portion of the combustion conduit; and an expansion joint coupling the combustion conduit to the penetration conduit so as to accommodate relative angular movement.
 17. The apparatus of claim 16 wherein: the expansion joint is an elastomeric expansion joint.
 18. The apparatus of claim 16 wherein: the expansion joint is a metallic expansion joint.
 19. The apparatus of claim 17 wherein: the expansion joint has a downstream flange secured to an upstream flange of the penetration conduit; the expansion device has an upstream flange secured to an apertured plate accommodating the combustion conduit in a slip fit having smaller clearance than a clearance between the combustion conduit and the penetration conduit.
 20. The apparatus of claim 16 further comprising: means for transferring a recoil force to building structure bypassing the vessel wall.
 21. The apparatus of claim 20 wherein: the means comprise a vertically sliding engagement with the building structure.
 22. The apparatus of claim 20 wherein: the means comprise a resilient damper.
 23. The apparatus of claim 21 wherein: the means for transferring a recoil force includes a plurality of elastomer bumpers.
 24. An apparatus for cleaning a surface within a vessel, the apparatus comprising: an elongate combustion conduit extending from an upstream end to a downstream end associated with an aperture in a wall of the vessel and positioned to direct a shock wave toward said surface; one or more hangers supporting the combustion conduit at one or more locations along a length of the combustion conduit; a penetration conduit between the wall aperture and an adjacent portion of the combustion conduit; an expansion joint coupling the combustion conduit to the penetration conduit so as to accommodate relative angular movement; and a damping unit for restraining the combustion conduit against thrust movement including a plurality of elastomer bumpers arranged on a rod, the rod engaging at least two struts coupling the combustion conduit to a fixed building structure. 